1. Entropy changes of pure substances: retrieving data from property tables.
Tds relations relate properties of any pure substance exactly to entropy change. But it is not convenient to use them.
Instead tabulated data for s are used, e.g.
Table B.1. for water.
Table B.5 for refrigerant R134a
The tabulated value s actually means the entropy change from chosen reference state which is assigned a value 0 (e.g. entropy of saturated liquid water is assigned a value 0 kJ/kg/K) at the triple point of water where t=0.010 C and P=0.61 kPa)
In the superheated vapor region and compressed liquid region (Table B.1.4) s can be calculated given P and T.
In the saturated liquid region:
s=sf+xsfg
When no compressed liquid data is available the saturated liquid table (e.g. Table B.1) can be used to get an approximate value

2. h-s plot or the Mollier diagram for a pure substance.
Horizontal line segment entropy change during an isenthalpic process (application: throttling)
Vertical line segment  enthalpy change during an isentropic process (application: turbine).
Constant pressure lines
are inclined straight lines in the two-phase region, since temperature is also
constant.
In the superheated region, isotherms lines become more and more horizontal as pressure is reduced (h=h(T) for an ideal gas.)
Concave curves in the superheated region. Diverge from one another as psat up means tsat up

3. An actual h-s chart (Mollier diagram) for water

4. T-s and h-s plots: checklist
Show critical point, SLL and SVL on T-s plot.
Show constant P lines on T-s plot.
Show constant v lines on T-s plot.
Show constant P lines on h-s plot. Inside the vapor dome, why straight lines; why inclined; why diverging from one another.
Show critical point, SLL, SVL on h-s plot.
Water 374 degrees C and 22 MPa